Apparatus for folding or corrugating sheet material



Oct. 26, 1965 J. J. ROBINSON APPARATUS FOR FOLDING OR CORRUGATING SHEET MATERIAL 4 Sheets-Sheet l Filed July 11,v 1962 mw mm w. m mm .Im s E M A lv ATTORNEY Oct. 26, 1965 Filed July 11, 1962 J. J. ROBINSON 3,213,665

APPARATUS FOR FOLDING OR CORRUGATING SHEET MATERIAL 4 Sheets-Sheet 2 INVENTOR.

\\ JAMES J. RoslNsoN H .f/- M 3 ATTORNEY Gat. 26, i965 J. J. ROBINSON 322365 APPARATUS FOR FOLDING GR CORHUGATING SHEET MATRAL Filed July 11, 1962 4 Sheets-Sheet 3 /IOB /IOO

INVENTOR.

JAME J. ROBINSON ATTORNEY Oct. 26, 1965 J. J. ROBINSON 3,213,665

APPARATUS FOR FOLDING OR CORRUGATING SHEE1 MATERIAL Filed July l1, 1962 y 4 Sheets-Sheet 4 INVENTOR.

JAMES J. ROBINSON ATTORNEY United States Patent O 3,213,665 APPARATUS FOR FOLDlNG R CORRUGATING SHEET MATERIAL Eames J. Robinson, indianapolis, ind., assignor to Twin Industries Corporation, Buffalo, N.Y., a corporation of Delaware Filed July 11, 1962, Ser. No. 209,138 16 Claims. (Cl. 72-385) This invention pertains to the art of metal forming apparatus and more particularly to a sheet metal folding or corrugating machine for forming transversely extending corrugations in a thin metal sheet.

The invention is particularly applicable to forming generally rectangular, transversely extending corrugations in a thin sheet metal material; however, it is to be appreciated that the invention has much 'broader applications and may Ibe used to form dierent shaped cor-ru-gations in various sheet materials.

The present invention is an improvement over the apparatus disclosed in my Letters Patent 2,983,302 wherein there is shown a crimping or corrugating apparatus having two die members reciprocally mounted to move toward and away from each other so that the forming 'blades carried by these die members produce transversely extending, reoccurring corrugations in a thin metal sheet as the sheet is passed Ibetween the blades. This prior type of apparatus also included a first set of cams for reciprocating the die members toward and away from each other and a second `set of cams for shifting one die member longitudinally back and forth with respect to the other die member to pull the sheet through the apparatus. In addition to this type of crimping or corrugating apparatus, other apparatus has been proposed for forming transverse corrugations in a thin metal sheet; however, these latter apparatus were comprised of a pair of rotating forming rolls between which thin metal material was passed. Such apparatus having forming rolls were found to be complicated to control, expensive to construct and susceptible to various structural failures and, accordingly, this type of forming apparatus has proven to be unsatisfactory in practice; especially, when a great number of accurately dimensioned corrugations must be formed at a rapid rate in a long sheet of material.

The present invention is directed toward an improved folding or corrugating apparatus of the general type disclosed in my above-mentioned Letters Patent and the improvements thereover are basically the provision of one set of drive cams for providing both the reciprocal and back and forth movement of the die members; an improved stroke adjusting means between the drive cam and the die member moving in the back and forth direction; and a convenient means for adjusting the innermost position of the die members with respect to the feedline of the thin met-al sheet passing through the apparatus.

ln accordance with the present invention, a folding or corrugating apparatus of the general type described is provided with a rotating drive cam, a slide connected to one of the die members and reciprocated by the drive cam and means for adjusting the stroke of the slide. The stroke adjusting means comprises a first member pivotalvly mounted on a first axis and forming a follower rid- ZIXES.

ice

In accordance with a further aspect of the present invention, a met-al folding or corrugating apparatus of the type having reciprocating die members is provided with a cam drive member; a rocker arm having a first end engageable with the drive member, and a second end connected to one of the die members; and on adjusting means between one of the members and one of the ends of the rocker arm for adjusting the lowermost position of the die member as it moves inwardly. This adjusting means comprises an adjustable first element having an inclined cam surface, a second element having an inclined cam surface, and a feed screw for moving the second element toward and away from the first element to change the adjusted position of the iirst element. There is also provided a `means on the feed screw for indicating the amount of -adjustment of the first element.

In accordance with another aspect of the present invention there is provided an apparatus for corrugating a sheet as the sheet passes therethrough on a predetermined feedline, wherein a low rise cam having only one cam surface, both reciprooates two die blocks and shifts one of these die blocks 'back and forth with respect to the other die Iblock to form the sheet.

The primary object of the present invention is the provision of a folding or corrugating apparatus having die members mounted to reciprocate toward and away from each other, which apparatus is durable in operation, easily set up for running various jobs and relatively simplified in comparison with the prior folding or corrugating apparatus.

A further object of the present invention is the provision of a folding or corrugating apparatus having die members mounted to reciprocate toward and away from each other, which apparatus includes only lone set of drive cams for reciprocating the die members toward and away from each other and for shifting one die member back and forth with respect to the other die member.

Another object of the present invention is the provision of a folding or corrugating apparatus having die members mounted to reciprocate toward and away from each other, which apparatus includes a set of 4operating cams having gradual rises as compared to prior apparatus of this type.

Yet another object Vof the present invention is the provision of a folding or corrugating apparatus having die members mounted to reciprocate toward and away from each other, which apparatus includes a simplified means for adjusting the innermost position of the reciprocating die members as they are moved toward a thin metal `sheet passing through the apparatus.

Still a further object of the lpresent invention is the` provision of -a folding or corrugating apparatus having die members mounted to reciprocate toward and away from each other which apparatus includes a device for shifting one die member back and forth with respect to the other die member, wherein the device is Ismall in size and provides a large range of stroke adjustments with only ya slight rise of the operating cam used to shift the `die member.

Another object of the present invention is the provision of a folding or corrugating apparatus having die members mounted to reciprocate toward and away `from each other, which apparatus includes a means for adjusting the back -and forth stroke of one die member with respect to the other die member, wherein the means comprises a rst member pivotally mounted on a first axis and having a follower adapted to ride on the drive cam of the apparatus, a second member pivotally mounted on a .second axis offset fro-m the first axis, an element spaced from the rst and second axes for operably connecting the two members and means for simultaneously, inversely adjusting the spacing of the element from the axes.

Yet a further object of the present invention is the provision of a folding or corrugating machine of the general type described which includes a means for adjusting the innermost position of the die members as they are moved toward a sheet passing through the apparatus, wherein the means comprises an adjustable rst element having an inclined cam surface, a second element having an inclined cam surface, a feed screw for moving the second element toward and away from the first element to change the adjusted position of the rst element, and means on the feed screw to indicate the amount of adjustment of the lirst element.

These and other objects and advantages will become apparent from the following description used to illustrate the preferred embodiment of the invention as read in connection with the accompanying drawings in which:

FIGURE 1 is a side elevational view of the preferred embodiment of the invention;

FIGURE 2 is a somewhat schematic partial side view illustrating the operation of the preferred embodiment of the present invention;

FIGURE 3 is a partial cross sectional front view of the preferred embodiment disclosed in FIGURE l;

FIGURE 4 is a cross sectional view taken along line 4-4 of FIGURE 3;

FIGURE 5 is a partial enlarged cross sectional view showing the die members in their innermost position;

FIGURE 6a-e are schematic views illustrating the operating steps of the preferred embodiment disclosed in FIGURE 1.

Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, FIGURE 1 shows a folding or corrugating apparatus A and a thin metal sheet B adapted to be passed through the apparatus A on a predetermined feedline so that the apparatus provides reoccurring, transversely extending corrugations C in the sheet B.

The apparatus A comprises an appropriately constructed frame 10 having a support base 11; drive cams 12, 14 rotatably mounted on opposite sides of frame 10; upper and lower rocker arm assemblies 16, 18 respectively; die assembly 20 having a rearwardly facing slide 22; and a stroke adjusting means 24.

Referring now in detail to the drive cams 12, 14 shown in FIGURES 1 and 3, an appropriate drive means, which for illustrative purposes is disclosed as a belt and pulley drive arrangement, is provided to rotate a shaft 32 having the cams secured thereon by appropriate means such as keys 34. The drive cams are arranged as a set wherein one cam is adjacent one side of the frame 10 and the other cam is adjacent the opposite side of the frame. Since the cams and the operating mechanism associated therewith are substantially identical on either side of the frame 10, only the cam 12 and the operating elements associated therewith will be discussed in detail; however, it is appreciated that t-he description of the one side of the apparatus A applies equally to the opposite side of the apparatus.

Cam 12, as is shown schematically in FIGURE 2, forms an important part of the invention and comprises a sector M having a radius R and extending substantially 180, a sector N having a radius R' and extending substantially 90, a sector O having a gradually increasing radius from R to R and extending approximately 40, and a sector T having a gradually decreasing radius from R to R and extending approximately 50. The radius R is slightly larger than the radius R. In practice the difference between the two radii is between .l0-.50 inch with the larger radius R being approximately 8.50 inches. As the length of radius R increases, the difference between the two radii may be correspondingly increased without changing the basic operation of the cam. The relationship of the radius of the cam to the amount of rise on the cam is very important to limit the inertia forces on the machine and provide smooth operation. Accordingly, with a radius R of 17 inches the rise should not exceed approximately 1.0 inch. As the rise increases sectors O and T have a more abrupt change which reduces the operational advantages of one cam surface control of the moving parts on the apparatus. The minimum rise of a 17 inch cam would be approximately .10 inch because small rises would be difficult to convert accurately into proper displacement of the parts controlled by the cam, Of course these same ratios of rise to diameter applies for different cam diameters. Since the difference between the radii R and R is only slight, a number of indicia 36 are provided to indicate the position of the high and low portions of the cam. As will be described later in detail, the cam 12 has only one cam surface defined by the outer periphery of the cam which, not only reciprocates the die members toward and away from sheet B, but also moves one die member back and forth longitudinally with respect to the other die member to pull the sheet B through the apparatus.

In operation of the apparatus as so far described, drive cams 12, 14 are rotated to oscillate rocker assemblies 16, 18 and thereby reciprocate a pair of die members toward and away from each other. Rotation of the drive cams also forces slide 22 back and forth in the longitudinal direction.

Referring now to the upper rocker arm assembly 16 which -is adapted to transmit reciprocal movement to a die member in die assembly 20, two spaced rocker arms 38 are joined at their forwardmost ends by a transversely extending pressure bar 40. The rocker arms 38 are pivotally mounted onto the frame by appropriate means such as pivot pins 42; and they are each provided with a follower 44 adapted to engage the outer cam surface of cams 12, 14. To assure that the follower 44 bears against the drive cams, the rocker arm assemblies 16 are provided with appropriate downward biasing means such as a coil spring 46.

The lower rocker arm assembly 18 comprises two spaced rocker arms 48 joined at their forwardmost ends by a transversely extending pressure bar 50 similar to pressure bar 40 joining the rocker arms 38. Each rocker arrn 48 is pivotally mounted onto frame 10 by appropriate means such as pins 52 and are oscillated by a follower 54 adapted to ride along the outer cam surface of the drive cams 12, 14. Appropriate means are provided for biasing the rocker arms 48 against the cams. By this construction, the cams oscillate the rocker arm assemblies to actuate the forming die members of the apparatus.

Each of the pressure bars 40, 50 is provided with a plurality of transversely spaced push -rods 60, any number of which may be provided; however, in the preferred embodiment, a push rod is positioned adjacent each end of both bars. The construction of only one push rod will be described; however, it is to be appreciated that this description applies equally to the other push rods. Each push rod 60 comprises a clevis 62 which carries a roller 64 pivoted about a pin 66, a shank 68 extending through an aperture 70 in the bar 50, and a guide pin 72 adapted to be received within a guide hole 74 on the bar 50 to prevent rotation of the push rod. The downwardmost end of shank 68 has an inclined cam surface 76 which extends into a chamber 78 within the bar 50. Also in the chamber 78 is a cam block 80 having an appropriate cam surface 82 adapted to match cam surface 76 of the shank 68. Cam block 80 has an appropriate threaded aperture 84 for threadably receiving a feed screw 86 having a shank 88 which is appropriately journaled in rocker arm 48 and restrained from axial movement by spaced collars 90, 92. The outwardmost end of shank 88 is provided with an appropriate head 94 which is so formed to receive a wrench for adjusting the position of the block with respect to shank 68 so that the spacing of roller 64 with respect to the bar 50 may be easily adjusted. To indicate the adjusted Iposition o f block 80, and, thus, the extended distance of roller 64, there is provided an appropriate means such as a dial on the outermost base of collar 90 which registers with appropriate indicia on the outer surface of the rocker arm 48 as is shown in FIGURE 1. In accordance with the preferred embodiment, the angle of the cam block 80 and the pitch of the feed screw 86 are so interrelated that one turn of the screw shifts the roller 64 .010 inch.

Referring in more detail to the die assembly 20, which is best shown in FIGURES 2, 3 and 4, there is provided an upper die shoe 100, a lower die shoe 102, and a pair of transversely spaced generally identical die guide plates 104 having rectangular openings 105 for receiving the ends of the die shoes. Adjacent the upper portion of each opening 105, there is provided a reciprocally mounted pin 106 extending through the upper die shoe and anchored thereto by pins 107 so that the die shoe 100 may be reciprocated back and forth within the opening 105. Above the die shoe 100 there is provided an upper die rain 108 having a forwardly extending shoulder 109 which is similar in construction to a lower die ram 110 below the die shoe 102 and having a forwardly extending shoulder 111. The respective die shoes and rams are affixed to each other by guide pins 112 which allow reciprocal movement between the ram and the shoe; and a plurality of coil springs 114 bias the rams away from their respective die shoes. To adjust the distance between the die shoes, there is provided a cam shoulder 120 on both ends of shoe 102 and extending into the openings 105 as is shown in FIGURE 1. Disposed below the cam shoulder 120 is a cam block 122 having an upwardly facing cam surface 124 and adapted to threadably receive a thread screw 126 having a shoulder 128 held within the die plate 104 to prevent axial movement thereof. Adjacent the outermost end of feed screw 126 is a dial ring 130 attached to the die guide plate 104 and having indicia which register with indicia on a dial collar 132 rigidly affixed onto the outer portion of the feed screw. To shift the cam block 122 with lrespect to the shoulder 120, the outer end of the feed screw 126 is provided with head 134 which may be adjusted by an appropriate wrench. Extending downwardly from the die shoe 102 is a locking bolt 136 received within the elongated slot 138 of die guide plate 104.

In adjusting the folding or corrugating apparatus, the die shoe 102 may be adjusted with respect to the die shoe 100 by loosening the locking bolt 136 and adjusting the block 122 with respect to the cam shoulder 120. The dial collar 132 indicates accurately the amount of adjustment in the distance between the die shoes so that this distance may be adjusted accurately without resorting to a completely trial and error method. The die shoes are vertically fixed with respect to the die guide plates 104; and the upper and lower die rams 108, 110 are mounted to be reciprocated with respect to these die shoes by the push rods 60 actuated with oscillation of rocker arm assemblies 16, 1S.

To form the transverse corrugations C in sheet B, each of the die rams 108, 110 carry a pair of forming blades 140 separated by appropriate spacers 142 and are clamped onto the rams by clamping rails 144 and bolts 146 as is shown in FIGURES 2-4. The particular dimensions of the blades and spacers do not form a part of the present invention; however, they are so dimensioned that the strip B may be corrugated by the two lower blades overlapping the two upper plates without scufiing or rupturing the metal strip B. As will be hereinafter described, the upper die shoe 100 and die ram 108 are moved longitudinally back and forth with respect to the lower die shoe so that the upper forming blades are reciprocated between the solid line position and the phantom line position inFIG- URE 5. In both of these positions, movement ofthe forming blades toward each other by the die rams forms corrugations in the sheet B. By adjusting the distance between die shoes 100, 102 to correspond with the height of corrugations lC and'adjusting the innermost positionof the upper and lower die rams 108, so that the respective forming blades extend inwardly a distance spaced from the opposite die shoes equal to the thickness of the sheet B, the forming blades bottom out on the opposite spacer or die shoe to give a set to each bend of the corrugations.

Referring to FIGURES 1 and 2, the slide 22 comprises a bearing plate fixedly secured onto the rear end of pins 106 and is biased away from the die guide plate 104 by appropriate biasing means such as coil springs 152 as is shown in FIGURE 1. Back and forth movement of the bearing plate 150 causes corresponding movement of the upper die shoe 100 and the upper die rarn 108 so that the forming blades 144 may be moved back and forth as indicated in FIGURE 5. The preferred embodiment of the means for moving plate 150 in a longitudinal direction will be hereinafter described in detail.

The stroke adjusting means 24 forms an important part of the present invention and in essence is an adjustable means for converting the slight rise of the cam surface on cam 12 into a substantial back and forth reciprocal movement of the slide 22. It is best shown in FIGURES 1 and 2 and comprises a lever 160 pivotally mounted on axis g and having a follower 162 engagingl the cam surface of cam 12 at a predetermined point 163 and a bearing surface 164 on the opposite side of the lever 160 from follower 162. It is to be appreciated that a similar means 24 rides along the cam 14, and this discussion applies equally to both stroke adjusting means. Spaced forward from lever is a second lever 170 pivotally mounted on axis h which axis is located on the side of the radial line through'the point 163 remote from the axis g. On the side remote from cam 12, lever is provided with an appropriate follower 172 adapted to contact bearing plate 150 to reciprocate the bearing plate and, thus, the die shoe 100 back and forth in accordance with the movement of the follower. A-s is shown, the lever 170 has a bifurcated construction defined by opposed arms 174, 176 adapted to rotatably mount a feed screw 178 extending therebetween. Threadably received on the feed screw 178 is a bearing cylinder 180 which is prevented from rotating by any appropriate means when the feed screw 178 is rotated by a head 182. Adjacent head 182 is a collar 184 which may be provided with indicia to indicate small adjustments of the vertical position of cylinder 180. To indicate greater vertical adjustment of cylinder 180, a pointer 186 is affixed to the external end of cylinder and registers with appropriately positioned scale 188 on lever 170. By using the scale 188 and collar 184, a Vernier is provided which will allow accurate indication of the stroke imparted to slide 22 by cam 12.

The geometry of means 24 is shown in detail in FIG- URE 2. Axes g and h are spaced from each other and are disposed on opposite sides of followers 162, 172. The distances between follower 162 and axis g and follower 172 and axis h are stationary and are not affected by any adjusting of the cylinder 180. The rise of cam 12 indicated as distance x shifts follower 162 back and forth this distance which in turn shifts bearing surface 164 back and forth a distance y. Since the spacing of cylinder 180 from axis g is greater than the spacing of follower 162 therefrom, the distance y is greater than the distance x. As cylinder 180 is shifted back and forth a distance y, the follower 172 is shifted back and forth a distance z, which back and forth movement is transmitted to bearing plate 150 against the force of springs 152. Distance z is greater than distance y because follower 172 is spaced further from axis lz than cylinder 180. Consequently, the back and forth strokes z of the slide 22 is substantially greater than the rise x of cam 12. By rotating the feed screw 178 in a reversed direction, cylinder 180 is moved upwardly for inverse adjustment with respect to axis g and h. The term inversed adjustment indicates a decrease in the distance from axis g and an increase in the distance from axis h or vice versa. By moving cylinder 180 toward axis g, the distance y is decreased because the spacing of the cylinder from axis g is decreased with respect to the spacing of the follower 162. The distance z is also decreased with respect to the distance y because the spacing of cylinder 180 from axis h is increased while the spacing of follower 172 remains constant. By reversing the rotation of feed screw 178, the cylinder 180 goes vertically downward to correspondingly increase the distance y with respect to the distance x and the distance z with respect to the distance y to increase the stroke of slide 22. By this arrangement, a substantial amount of adjustment can be provided with a relatively compact adjusting mechanism. In essence the stroke adjusting means 24 comprises a first member pivotally mounted about a first axis and having the follower adapted to ride on the drive cam, a second member pivotally mounted on a second axis offset from the first axis, an element spaced from the first and second axis for operably connecting the two members and means for simultaneously inversely adjusting the spacing of the element from the axes.

Referring now to FIGURES 6a-6e, the operating steps of a folding or corrugating machine constructed in accordance with the present invention are illustrated wherein the structural elements of the apparatus are diagrammatically represented. The die rams 108, 110 are illustrated as reciprocating bifurcated members having spaced blades which are adapted to be moved into overlapping relationship with each other. The slide 22 is shown as being affixed onto die ram 108 and in direct sliding contact with drive cam 12; however, it is to be appreciated that the stroke adjusting means 24 is actually interposed between the cam and the slide. The rocker arm assemblies 16, 18 are shown as pivoting lengths contacting drive cam 12 at diametrically opposite positions and operably connected onto the die rams. Structural details have been eliminated for the purposes of simplicity. In FIGURE 6a, the rocker arm assemblies 16 and 18 contact cam 12 at a portion having the larger radius R and the slide 22 contacts the cam on a portion having the small radius R. Accordingly, the die rams 108, 110 are in their innermost positions and form a corrugation C as shown. After rotation of the cam 12 45, the rocker arm assembly 18 is shifted from the large radius portion to the smaller radius portion of the cam which lowers the die ram 110 and leaves sheet B impaled upon the ram 108. Slide 22 is just beginning its movement to the right. This operation step is shown in FIGURE 6b. Further rotation of the drive cam 12 is shown in FIGURE 6c wherein the slide 22 is shifted to the right, drawing the sheet B through the machine. Movement of the slide is caused by shifting the slide from the small radius portion of the cam R to the large radius portion of the cam. Referring now to FIGURE 6d, the drive cam 12 has been rotated 90 which shifts the lower rocker arm assembly 18 from the small radius portion to the radius portion; therefore, die ram 110 is forced upwardly to form another corrugation in sheet B. After a 45 angle shift of the drive cam 12 as shown in FIGURE 6e, the upper rocker arm assembly 16 shifts from the large radius portion to the small radius portion to thereby raise die ram 108. Rotation of the cam a further 90 moves slide 22 from the large radius portion to the small radius portion ofthe cam and is thus shifted to the left. After the cam is rotated a further 45, the elements are in a position shown in FIGURE 6a. These operational steps are repeated to produce a plurality of transversely extending reoccurring corrugations C.

Referring again to FIGURE 1, there is provision for maintaining a predetermined tension upon sheet B, which in the preferred embodiment is disclosed as a single arm 200 having a lower strip engaging roll 202 wherein the gravity force on the arm maintains a slight tension on the strip as it is being pulled through the machine. Referring 8 to FIGURE 2, there is provided a guide apron 204 for guiding the strip B into the space between the upper and lower die used, 100, 102 respectively.

The invention has been discussed in connection with one preferred embodiment thereof; however, it is to be appreciated that the invention is not intended to be limited to the particular structural embodiment disclosed. To the contrary, various structural changes may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim:

1. An apparatus for corrugating a sheet as said sheet passes therethrough on a predetermined feedline, said apparatus comprising a pair of die blocks on opposite sides of the feedline, a rotating drive cam having a single cam surface, a first lever means for reciprocating one of said die blocks toward and away from said feedline, a second lever means for reciprocating the other of said die blocks toward and away from said feedline, and a third lever means for shifting one of said die blocks back and forth with respect to the other of said die blocks, each of said lever means engageable with said cam single surface whereby said reciprocation and shifting of said die blocks is controlled by rotation of said drive cam, said one cam surface having a first portion extending through an angle of approximately a second portion extending through an angle of substantially less than 180 and two gradual transition portions joining said first and second portions, the radius of said first portion being greater than the radius of said second portion.

2. An apparatus as defined in claim 1 wherein said difference between the radii of said first and second portions divided by the radius of the first portion is within the range of .l0/8.50 to .S0/8.50.

3. In a folding apparatus adapted to form transverse corrugations in a sheet passing through the apparatus on a feed line comprising a first and a second die member, first means for reciprocating said die members toward and away from said sheet, second means for causing back and forth movement of said first die member along said feed line and with respect to said second die member and in phase with said reciprocation of said die members, and a rotating drive cam having a contoured cam surface controlling said reciprocation movement of said die members, the improvement comprising: said second means including a slide connected with said first die member, and a movement magnifying means operably connecting said slide and said contoured cam surface, said movement magnifying means comprising a first member pivotally mounted on a first axis and having a first follower riding on said cam surface, a second member pivotally mounted on a second axis offset from said first axis, an element spaced from said first and second axes and between said axes for operably connecting said pivot members, mechanical means for connecting said second pivotal member onto said slide and adjusting means for simultaneously,

inversely adjusting said spacing of said elements from said axes, said first follower means and said mechanical means being spaced from said first and second axes, respectively, to convert the contour of said cam surface into an increased movement of said slide.

4. The improvement as defined in claim 3 wherein said first pivot member comprises a first lever having a bearing surface facing said second pivot member and adapted to bear against said element and said second pivot member comprises a second lever and means on said second lever for mounting said adjusting means.

5. The improvement as defined in claim 4 wherein said element comprises a bearing block, and said adjusting means comprises a positioning means for securing said block in adjusted longitudinal position on said second member and spaced from said second axis.

6. The improvement as defined in claim 5 wherein said positioning means comprises a first cam means on said block and a second cam means on said second lever.

7. The improvement as defined in claim 6 wherein said first cam means comprises a threaded aperture in said block and said second cam means comprises a rotatable feed screw extending into said aperture and journaled onto said second lever.

8. The improvement as defined in claim 7 wherein said second lever is provided with a first and a second indicator, said first indicator adjacent said feed screw to indicate the angular position of said feed screw and said second indicator adjacent said block to indicate the longitudinal position of said block with respect to said second lever.

9. The improvement as defined in claim 3 wherein said element comprises a bearing block, and said adjusting means comprises a positioning means for securing said block in adjusted longitudinal position on said second pivot member and spaced from said second axis.

10. The improvement as defined in claim 9 wherein said positioning means comprises a first cam means on said block and a second cam means on said second pivot member, said first cam means comprises a threaded aperture in said block and said second cam means comprises a rotatable feed screw extending through said aperture and journaled onto said second pivot member.

11. The improvement as defined in claim 10 wherein said second pivot member is provided with a first and a second indicator, said first indicator adjacent said feed screw to indicate the angular position of said feed screw and said second indicator adjacent said block to indicate the longitudinal position of said block with lrespect to said second pivot member.

12. The improvement as defined in claim 3 wherein said adjusting means comprises a first cam means on said element and a second cam means on said second pivot member.

13. The improvement as defined in claim 12 wherein said first cam means comprises a threaded aperture in said element and said second cam means comprises a rotatable feed screw extending through said aperture and journaled onto said second pivot member.

14. The improvement as defined in claim 13 wherein said second pivot member is provided with a first and second indicator, said first indicator adjacent said feed screw to indicate the angular position of said feed screw and said second indicator adjacent said element to indicate the longitudinal position of said element with respect to said second pivot member.

15'. An apparatus for corrugating a sheet as said sheet passes therethrough on a predetermined feed line, said apparatus comprising a first and a second die member, first lever means for reciprocating said first die member toward and away from said sheet, second lever means for reciprocating said second die member toward and away from said sheet, means for causing back and forth movement of said first die member along said feed line and with respect to said second die member and in phase with said reciprocation of said die members, and a rotating drive cam having a single cam surface for controlling said reciprocation and back and forth movement of said die members, said first and second lever means being driven by said cam surface and said back and forth movement causing means being driven by said cam surface, said cam surface having a first portion with a radius R and a second portion with a radius R with R-R/R being in the range of .l0/8.50 to .S0/8.50 and said back and forth movement causing means including a means for amplifying the difference between R and R whereby said back and forth movement of said first die member with respect to said second die member is substantially greater than R-R'.

16. An apparatus as defined in claim 1S wherein said first portion of said cam surface extends through an angle of at least approximately and said second portion of said cam surface extends through an angle substantially less than 180.

References Cited by the Examiner UNITED STATES PATENTS 2,025,600 12/35 Loop et al 74--568 2,489,125 11/49 Dyson 153-76 2,983,302 5/ 61 Robinson 153-76 2,997,888 8/61 Rust 74-522 CHARLES W. LANHAM, Primary Examiner. MICHAEL V. BRINDISI, Examiner. 

3. IN A FOLDING APPARATUS ADAPTED TO FORM TRANSVERSE CORRUGATIONS IN A SHEET PASSING THROUGH THE APPARATUS ON A FEED LINE COMPRISING A FIRST AND A SECOND DIE MEMBER, FIRST MEANS FOR RECIPROCATING SAID DIE MEMBERS TOWARD AND AWAY FROM SAID SHEET, SECOND MEANS FOR CAUSING BACK AND FORTH MOVEMENT OF SAID FIRST DIE MEMEBR ALONG SAID FEED LINE AND WITH RESPECT TO SAID SECOND DIE MEMBER AND IN PHASE WITH SAID RECIPROCATION OF SAID DIE MEMBERS, AND A ROTATING DRIVE CAM HAVING A CONTOURED CAM SURFACE CONTROLLING SAID RECIPROCATING MOVEMENT OF SAID DIE MEMBERS, THE IMPROVEMENT COMPRISING: SAID SECOND MEANS INCLUDING A SLIDE CONNECTED WITH SAID FIRST DIE MEMBER, AND A MOVEMENT MAGNIFYING MEANS OPERABLY CONNECTING SAID SLIDE AND SAID CONTOURED CAM SURFACE, SAID MOVEMENT MAGNIFYING MEANS COMPRISING A FIRST MEMBER PIVOTALLY MOUNTED ON A FIRST AXIS AND HAVING A FIRST FOLLOWER RIDING ON SAID CAM SURFACE, A SECOND MEMBER PIVOTALLY MOUNTED ON A SECOND AXIS OFFSET FROM SAID FIRST AXIS, AN ELEMENT SPACED FROM SAID FIRST AND SECOND AXES AND BETWEEN SAID AXES FOR OPERABLY CONNECTING SAID PIVOT MEMBERS, MECHANICAL MEANS FOR CONNECTING SAID SECOND PIVOTAL MEMBER ONT SAID SLIDE AND ADJUSTING MEANS FOR SIMULTANEOUSLY, INVERSELY ADJUSTING SAID SPACING OF SAID ELEMENTS FROM SAID AXES, SAID FIRST FOLLOWER MEANS AND SAID MECHANICAL MEANS BEING SPACED FROM SAID FIRST AND SECOND AXES, RESPECTIVELY, TO CONVERT THE CONTOUR OF SAID CAM SURFACE INTO AN INCREASED MOVEMENT OF SAID SLIDE. 